Capacitive Touch Sensor Pressure Detection Layer Integration

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Solution Overview

Problem

Current touch input devices cannot effectively detect the magnitude of touch pressure on a touch screen without compromising the performance of the display module, particularly in terms of visibility and optical transmittance.

Innovation Solution

A touch input device is designed with a capacitance-type touch sensor panel and a pressure detection module that includes drive and receiving electrodes, where the pressure detection module is integrated with the display module to detect touch pressure without degrading the display's visibility and optical transmittance, using a spacer layer to maintain the display's integrity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a pressure detection module is integrated with the display module to detect touch pressure, then the ability to detect touch pressure magnitude is improved, but the visibility and optical transmittance of the display module deteriorate

Engineering Contradiction:
Improvetouch pressure detection capabilityVSAvoiddisplay visibility and optical transmittance
Core Design Contradiction:
Measurement precisionVSIllumination intensity

Solution Approach 1:

The pressure detection module is positioned at the rear side of the display module, utilizing the z-dimension (depth layer) rather than occupying the optical path in the x-y plane. This spatial reconfiguration allows pressure sensing electrodes to be placed in a separate layer without interfering with light transmission through the display, thereby maintaining visibility while enabling pressure detection

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

A spacer layer is introduced as an intermediary component between the display module and the pressure detection module. This spacer maintains a specific distance between the two modules, preventing direct contact that would block light while still allowing the pressure detection electrodes to sense touch pressure through the spacer layer, thus preserving optical transmittance

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If the pressure detection module is placed close to the display module, then the structural integration is improved, but the optical transmittance of the display module deteriorates

Engineering Contradiction:
Improvestructural integrationVSAvoidoptical transmittance
Core Design Contradiction:
Device complexityVSIllumination intensity

Solution Approach 1:

The pressure detection module is positioned at the rear side of the display module, utilizing the z-dimension (depth layer) rather than occupying the optical path in the x-y plane. This spatial reconfiguration allows pressure sensing electrodes to be placed in a separate layer without interfering with light transmission through the display, thereby maintaining visibility while enabling pressure detection

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

A spacer layer is introduced as an intermediary component between the display module and the pressure detection module. This spacer maintains a specific distance between the two modules, preventing direct contact that would block light while still allowing the pressure detection electrodes to sense touch pressure through the spacer layer, thus preserving optical transmittance

Inventive Principle:
Principle #24Intermediary (Mediator)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The device successfully detects both touch position and pressure magnitude without reducing the display's visibility or optical transmittance, enhancing user interaction while maintaining the display's performance.

Implementation Method 1

a capacitance-type touch sensor panel configured to detect a touch position on a touch screen

Methodology Applied
Scientific EffectCapacitance: Capacitance

Implementation Method 2

the plurality of sensor electrodes configured to capacitively sense positional information associated with user input in a sensing region

Methodology Applied
Scientific EffectCapacitance: Capacitance

Data Source

PatentEP3048514B1Touch input device
Publication Date: 2024.10.09 HIDEEP INC
  • EP3048514B1 patent drawingFigure 1~2a
  • EP3048514B1 patent drawingFigure 2b~4
  • EP3048514B1 patent drawingFigure 5~6a

AI summary

A smartphone includes: a cover layer; a display module which is located under the cover layer and comprises an LCD panel comprising a liquid crystal layer, and a first glass layer and a second glass layer between which the liquid crystal layer is placed, and comprises a component configured to cause the LCD panel to perform a display function; a pressure electrode which is located under the display module; and a shielding member which is located under the pressure electrode. At least a portion of a touch sensor which senses touch in a capacitive manner is located between the first glass layer and the second glass layer. The touch sensor comprises a plurality of drive electrodes and a plurality of receiving electrodes. A touch position is detected by a sensing signal which is outputted from the touch sensor. A magnitude of a touch pressure is detected based on a change amount of capacitance outputted from the pressure electrode.